Since the discovery by the University of Dundee Group in the early 1970's, that high-quality, low density of states amorphous silicon could be produced from the decomposition of silane (SiH4) gas in a glow discharge, amorphous silicon photovoltaic devices, especially amorphous silicon photovoltaic panels have emerged as a dominant force in the marketplace. These devices are much cheaper to manufacture in comparison to former crystalline devices. As a result, there has been renewed interest by industry in developing photovoltaic assemblies which can harness solar radiation and convert it directly to electricity on a large scale basis. The concept of "solar fields" as they are termed in the art, is actively being researched. To date, a number of experimental solar fields have been installed throughout the United States for scientific study.
While the general costs of producing the panels themselves have been reduced dramatically, the labor costs associated with installing the support structures for the panels remain high. For example, a typical one mega watt field might contain fifty-six rows of panels with one hundred ten or more support posts per row for a total of more than six thousand support posts. Under conventional methods of installation, each of the six thousand+ posts must be individually mounted, oriented and leveled to specification in order to properly support the photovoltaic panels and maintain maximum efficiency of the solar field. Additional expenses are required to employ highly skilled men and women knowledgeable in the assembly of photovoltaic panels.
Various designs for templates used to drill underwater wells and drive piles into the sea-bottom are presently in operation. For example, U.S. Pat. No. 4,687,062 issued to Beghetto et al. discloses a light-weight, adjustable undersea template of variable dimensions for use in drilling wells under the sea floor. In operation, the template is leveled with the seabed and secured to the underlying terrain by cemented mooring piles.
U.S. Pat. No. 4,180,349 issued to Van Bilderbeek discloses a method for using an underwater template having a plurality of pile housings through which piles are driven into the earth at the sea floor to fix the template in place. The template is provided with grooves or lands and the pile section within the housing or jacket is expanded into mechanically interlocked relation in the grooves and with the lands by the application of an internal expansive force initiated or controlled from a remote location, such as from a platform or vessel on top of a body of water.
U.S. Pat. No. 4,110,993 issued to Heerema discloses an apparatus for driving piles into the sea-bottom from the support of a substructure resting on the sea-bottom of a working island to be installed. The Heerema apparatus comprises a plurality of support construction attached to a column each having guide passage openings for the piles and the followers.
U.S. Pat. No. 4,637,757 issued to Aagaard discloses a method and apparatus for anchoring a tension leg platform to the sea floor. The platform comprises a hollow pile that decreases in internal diameter partially down the length of the pile and contains 50 to 100 barbs placed at approximately 90 degrees to the axis of the pile. The platform accommodates a spreader tool that may be inserted into the pile to force the barbs outwardly.
While each of the references cited above discloses the use of a template to install a support structure, in all instances they are limited to the pile forging art.
Apart from underwater applications, the time and labor expenses associated with conventional methods of installing support structures in the ground in general have been acknowledged by the industry and have to some extent hindered the development of solar fields. However, if any one of these factors could be eliminated or reduced, the overall costs of installing photovoltaic panel support structures would be greatly reduced. As a result, the installation of photovoltaic panels in solar fields would be more economically feasible and solar energy collection systems would be accepted by industry as a true alternative to conventional energy generation systems.